At our local bike Co-op, we have a 10-pound bin of every sort of hub cone. I'd bet I could find a dozen compatible cones and have yours replaced and you out the door for less than $10.
We've never failed at restoring decent quality cup and cone hubs.
Unlike cartridge bearing hubs, which are generally throw-aways. We cannot stock a multitude of obscure carts, and many times we cannot get the old ones out.
Listen up: your local shops do have the replacement cones - and in stock. They are in some drawer, or they can be scavenged from a taco'd wheel in the back. Your shop staff are not motivated enough to find them, plus they see more profit in selling you a new set of wheels.
The way you deal with this is to make it clear, right from the first sentence, that no matter what happens, you are not going to buy a new wheel - at least from them.
Then drop a stack of $20 bills on the counter, and ask them how much it is going to take to find this part. Then watch them scurry.
Bike shop guys love cash. Only cash.. go figure.